AIX FAQ update - Mailing list pgsql-patches

FAQ_AIX in 8.1.0 contains outdated information about how to deal with
postgres problems due to readline.  The attached patch replaces that
section of it with better ways of handling the problem.

--
Seneca Cunningham
scunning@ca.afilias.info
--- FAQ_AIX    2005/12/05 19:49:10    1.1
+++ FAQ_AIX    2005/12/05 19:54:06
@@ -114,62 +114,68 @@

 http://www.han.de/~jum/aix/ldd.c
 ---
-From: Christopher Browne <cbbrowne@ca.afilias.info>
-Date: 2005-11-02

-On AIX 5.3 ML3 (e.g. maintenance level 5300-03), there is some problem
-with the handling of the pointer to memcpy.  It is speculated that
-this relates to some linker bug that may have been introduced between
-5300-02 and 5300-03, but we have so far been unable to track down the
-cause.
+AIX, readline, and postgres 8.1.x:
+----------------------------------

-At any rate, the following patch, which "unwraps" the function
-reference, has been observed to allow PG 8.1 pre-releases to pass
-regression tests.
-
-The same behaviour (albeit with varying underlying functions to
-"blame") has been observed when compiling with either GCC 4.0 or IBM
-XLC.
-
------------- per Seneca Cunningham -------------------
-
-The following patch works on the AIX 5.3 ML3 box here and didn't cause
-any problems with postgres on the x86 desktop.  It's just a cleaner
-version of what I tried earlier.
-
-*** dynahash.c.orig Tue Nov  1 19:41:42 2005
---- dynahash.c  Tue Nov  1 20:30:33 2005
-***************
-*** 670,676 ****
-
-
-            /* copy key into record */
-            currBucket->hashvalue = hashvalue;
-!           hashp->keycopy(ELEMENTKEY(currBucket), keyPtr, keysize);
-
-
-            /* caller is expected to fill the data field on return */
-
-
---- 670,687 ----
-
-
-            /* copy key into record */
-            currBucket->hashvalue = hashvalue;
-!           if (hashp->keycopy == memcpy)
-!           {
-!               memcpy(ELEMENTKEY(currBucket), keyPtr, keysize);
-!           }
-!           else if (hashp->keycopy == strncpy)
-!           {
-!               strncpy(ELEMENTKEY(currBucket), keyPtr, keysize);
-!           }
-!           else
-!           {
-!               hashp->keycopy(ELEMENTKEY(currBucket), keyPtr, keysize);
-!           }
-
-
-            /* caller is expected to fill the data field on return */
-
------------- per Seneca Cunningham -------------------
+If make check doesn't work on AIX with initdb going into an infinite
+loop or failing with child processes terminated with signal 11, the
+problem could be the installed copy of readline.  Previously a patch to
+dynahash.c was suggested to get around this, don't use it, better ways
+to get postgres working exist.
+
+See <http://archives.postgresql.org/pgsql-patches/2005-11/msg00139.php>
+for details about the problem.
+
+Working around the problem:
+---------------------------
+1) Use the new 8.2devel backend Makefile:
+After the matter of readline's export list and the problems that were
+occurring on AIX because of it being linked to the backend, a filter
+to exclude unneeded libraries from being linked against the backend was
+added.  Get revision 1.112 of src/backend/Makefile from CVS and replace
+the copy that came with postgres with it.  Build normally.
+
+2) Use libedit:
+There are a few libedit ports available online.  Build and install the
+desired port.  If libreadline.a can be found in /lib, /usr/lib, or in
+any location passed to postgres' configure via "--with-libraries=",
+readline will be detected and used by postgres.  IBM's rpm of readline
+creates a symlink to /opt/freeware/lib/libreadline.a in /lib, so merely
+excluding /opt/freeware/lib from the passed library path does not stop
+readline from being used.
+
+If the linker cannot avoid finding libreadline.a, use revision 1.433
+configure.in and 1.19 config/programs.m4 from CVS, change 8.2devel to
+the appropriate 8.1.x in configure.in and run autoconf.  Add the
+configure flag "--with-libedit-preferred".
+
+If the version of libedit used calls its "history.h" something other
+than history.h, place a symlink called history.h to it somewhere that
+the C preprocessor will check.
+
+3) Configure with "--without-readline":
+postgres can be configured with the option "--without-readline".  When
+this is enabled, postgres will not link against libreadline or libedit.
+psql will not have history, tab completion, or any of the other niceties
+that readline and libedit bring, but external readline wrappers exist
+that add that functionality.
+
+4) Use readline 5.0:
+Readline 5.0 does not induce the problems, however it does export
+memcpy and strncpy when built using the easy method of "-bexpall".  Like
+4.3, it is possible to do a build that does not export these symbols,
+but it does take considerable manual effort and the creation of export
+files.
+
+References
+----------
+"AIX 5L Porting Guide"
+  IBM Redbook
+  http://www.redbooks.ibm.com/redbooks/pdfs/sg246034.pdf
+  http://www.redbooks.ibm.com/abstracts/sg246034.html?Open
+
+"Developing and Porting C and C++ Applications on AIX"
+  IBM Redbook
+  http://www.redbooks.ibm.com/redbooks/pdfs/sg245674.pdf
+  http://www.redbooks.ibm.com/abstracts/sg245674.html?Open